Balanced Microphone Preamp - As I said in my cheapo digital audio project document, I was going to build a microphone preamp to attach a Behringer ECM8000 measurement microphone to line input of my minidisc deck.  After scanning the web to see if similar projects existed, I basically found three kinds - ones that used transformers    (ie.  pretty expensive to start with) and some even followed those with tubes and another transformer    (damn expensive) .   __ Designed by © Madis Kaal

Balanced Microphone Preamp  - Rugged design includes a 3-band equaliser.  It also features balanced and unbalanced outputs, and can drive a stereo or guitar amplifier.__ SiliconChip

Basic PIC18F4550 USB Communication Interface - When the device is connected to the computer, a Virtual COM Port    (VCP) will be created.  This is shown at the Device Manager Window under Ports    (COM & LPT) .  In this case, COM5 was created when the PIC18F4550 was attached to the USB Port.  It may be interesting to note that if you plug in your PIC in different USB ports, the VCP created will be different.  

Basic routine simplifies factoring - 09/12/97 EDN-Design Ideas -  Logarithms greatly simplify mamatical operations.  Factoring, however, presents a problem  Pocket calculators are clumsy when it comes to that operation.  The program factor.   bas   (Listing 1]is a convenient alternative if you want to obtain results in 3 minutes or less   (that is, turn on  computer, put  disk in  b  drive, select "qbasic," run  program, Design by Alan Land, Keystone Digital Co, Pittsburgh, PA

Basic Stamp Computer Eases Prototyping hassles - 04/09/98 EDN-Design Ideas -    (File has many circuits.  Scroll to find this one) Many of today's complex ICs use a common three-wire serial interface to provide programming access.  These ICs typically end up in circuits that include a µC or a CPU, and the controller or CPU then has the burden of programming the serially controlledseveral circuits included, scroll the find this one Design by Med Dyer, Jabra Corp, San Diego, CA

Basic Stamp I & PC Relay Controller - This project shows you how to build a relay controller using the Basic Stamp I interfaced to the PC serial port.    The Visual Basic 5 software developed for the interface lets you interact with the Basic Stamp to turn ON/OFF up to    (2) relays attached to the Basic Stamp I/O pins.    As shown below in the screen capture of PC-Relay, it's easy to select the desired com port using the drop-down menu __ Designed by Reynold's Elec

Battery Powered Lap Top Computer Power Supply - DN18 Design Notes__ Linear Technology/Analog Devices

Beacon Spinner LEDs - Our BEACONER - B8 has many applications; Manual press the push button to light 8 LEDs in sequence! Automatic, short the switch to automatically light 8 LEDs in sequence, draw attention and have fun! The unique small design will allow you to mount it almost anywhere.  Operate it with 9V battery, 12V car battery, four 1.5V batteries, or via one of our battery simulator kits.  The alternative uses are endless.   __ Contact: Kit from Elich Industrial Development, Corp

Beam Robot - PIC Project  Most of the BEAM robots I've seen on the net are using hardware analog electronics.  It seemed that a PIC would work very well for this kind of project.  Very little extra circuitry is needed to do both forword and backword walking sequences along with a few other tricks.  The PIC16F818 has a lot of features that work well in this situation.   __ Designed by Luhan Monat - Mesa Arizona

Bench Supply - PIC Project  This unit delivers 0 to 20 volts at up to 4 amps in 0.1volt increments.  The entire device runs on a PIC16F870    (about $3 in small quantities) .  This is basically a switching power supply with the voltage regulation done in software.  The PIC used here has analog inputs    (used to measure voltage and current) and hardware PWM    (pulse width modulation) output used to control the power.   __ Designed by Luhan Monat - Mesa Arizona

Better Cheap Video - PIC Project  This device uses a PIC16F1825 for improved performance.  Many of its internal features make it a dandy device for this application.   __ Designed by Luhan Monat - Mesa Arizona

Better, faster, random numbers - PIC Project  Many random number generators are software versions of the hardware shift register feedback circuit.  Two problems with this approach are that this operation is usually clumsy in software and the results have some noticeable patterns.   __ Designed by Luhan Monat - Mesa Arizona

Biasing MMIC Amplifiers e.g. ERA SERIES - AN-60-010 Application Note__ MiniCircuits.com

Bi-color LED Project - There are several projects on this page.  Please scroll down to find the LED Chaser.   __ Designed by Jason KE4NYV from Roanoke, Virginia

Bike Device - PIC Project  For starters, I mounted a 7 amp-hour gel-cell on the frame so that I wouldn't have to keep buying batteries for the headlight.  The headlight is a 12 watt Malibu light from Home Depot complete with a very good diffraction lens.  The horn is a scavenged auto alarm from Walmart.  I just use the horn with.   __ Designed by Luhan Monat-Mesa Arizona

Blue Clock (Atmel Atmega8535 microcontroller) - The main idea behind this project was to make Christmas gifts for friends and family that would be somewhat useful.  A clock was chosen simply because it is something that everyone uses and it would be relatively easy to complete.  Also,  __ Designed by Matt Meerian

Bluetooth Controlled Model Car - Control an RC car with any bluetooth enabled device.

Boot Loader for TMS320 Uses Bytewide EPROM - 04/25/96 EDN-Design Ideas - The price of high-speed DSP chips continues to drop.  The devices pack a lot of horsepower into small packages and are widely available.  In contrast, high-speed   (<-4-nsec]EPROMs are not only expensive, but also scarce.  To enhance the usefulness of their chips, DSP-chip manufacturers include an onboard boot-loader ROM Design by Robert Richards, Digital Audio Corp, Raleigh, NC

Bootstrapped Boost Converter operates at 1.8 Volt - 04/23/98 EDN-Design Ideas - NOTE : File contains multiple circuits scroll to find this circuit.   Many circuits, such as those that use batteries or solar cells, must operate in the face of decreasing supply voltages.  The circuit in Figure 1  maintains the maximum load current as the supply voltage drops.  The regulator boosts a 2.5 to 4.2V input to 5V Design by Tom Gross, Linear Technology, Milpitas, CA

Bridge Adaptor for Stereo Power Amplifiers - Would you like to connect a stereo amplifier in "bridge mode" in order to deliver double the power to a single loudspeaker system? This simple adaptor allows you to do it, without any modifications being necessary to the power amplifiers themselves.__ SiliconChip

Bright 20W LED Floodlight - Last February, we published a DIY 10W LED Floodlight, which has been enormously popular.  We said that one was almost blinding - but to paraphrase Croc Dundee, that's not bright.  THIS one is BRIGHT!__ SiliconChip

Build a Beam-Break Flash Trigger - Here's an easy-to-build accessory for the Time Delay Photoflash Trigger described in our February 2009 issue.  It triggers the delay unit and your photoflash in response to an object interrupting an invisible beam of infrared    (IR) light.  Alternatively, it can be used on its own to directly trigger a photoflash.__ SiliconChip

Build a Brownout Protector - What is a "brownout"? This rather graphically describes what happens to your lights when the AC mains voltage drops dramatically - they get very dim.  But apart from dim lights, brownouts are a fatal hazard to induction motors, as used in air conditioners, pumps, dishwashers and a lot of other appliances.__ SiliconChip

Build a charger for your iPod or MP3 player - Charge your iPOD without connecting it to a computer!__ SiliconChip

Build a Compact 12V 20W Stereo Amplifier - Amplifiers which run from 12V DC generally don?t put out much power and they are usually not hifi as well.  But this little stereo amplifier ticks the power and low distortion boxes.  With a 14.4V supply, it will deliver 20 watts per channel into 4-ohm loads at clipping while harmonic distortion at lower power levels is typically less than 0.03%.__ SiliconChip

Build a Digital Spirit Level - This project is really on the errr level.  It's an inclinometer, an electronic version of the old spirit level except that this one gives a digital readout of the angle of any flat surface in 0.1° increments from 0-360°.  A MEMS accelerometer chip, as found in tablets and smart phones, is at the heart of the project.__ SiliconChip

Build a Hot Wire Cutter - It's easy to build and lets you cut plastic foam without mess.__ SiliconChip

Build a LED Dice - A PIC microcontroller makes the circuit really simple.  We tell you how it was designed and show you how to build it.__ SiliconChip

Build a PIC Controlled DDS VFO 0 to 6 MHz - This is NOT meant as a detailed building instruction for a DDS VFO.  It is only a few fragments from my experimental work in the shack.  This is "as is" information.  It may contain errors.   However, my own prototype works very well. __ Designed by Johan Bodin, SM6LKM

Build a PIC Controlled DDS VFO 0 to 6 MHz - This is NOT meant as a detailed building instruction for a DDS VFO.  It is only a few fragments from my experimental work in the shack.  This is "as is" information.  It may contain errors.   However, my own prototype works very well. __ Designed by Johan Bodin, SM6LKM

Build an AVR ISP Serial Programmer - It allows you to reprogram your AVR micro in a flash, without even removing it from the application circuit.__ SiliconChip

Build the Picman Programmable Robot - A PIC microcontroller lets you program in the commands.__ SiliconChip

Button Code-Single Button Code Entry SystE - M - The Button Code is a system that allows a single button to act as a keypad.  The user enters a 4 digit code into the system using button taps.  The button can be placed where the public can access it since like a keypad there are many combinations to